From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D6AD522157A; Wed, 26 Feb 2025 15:20:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740583206; cv=none; b=EHWuSS4qhj8yCEsyM/VZqWPcUk+bIaLzx6aS0rcJ32TSeTafPMQPcLqZoDjL6OFILQRRVHI2PkG6YbOhjG61kVElu8ZG5SRgKWHZz1jOBr7V7Q84N2HyqLAJiGvjDabn4tn6lH91nLJFupfhcEpEBmHFSlQeHzHU+4wM2mYWk0Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740583206; c=relaxed/simple; bh=CedHuBhU4dG6Z7WShc/tqSWOqWeKxnRhgco2OyGymr4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ncKUQgbLwvikFZ6iMxsoY2gBcJpFMFAKVFtv4hd3NPYnW1NIC5Q8zrNq/LHrqQUCYSfIuYDlgAVUYm4J5mPP0zo5LCukZ2va+z/VCVT+FUfOUQpYKXQ4zDhPuoRq/PL0i3QniF1qMROnv8kjiITXDRoRbgg9D0aCvrhRM1Zw8Lg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cA/IzGhK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="cA/IzGhK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C6C24C4CED6; Wed, 26 Feb 2025 15:20:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1740583205; bh=CedHuBhU4dG6Z7WShc/tqSWOqWeKxnRhgco2OyGymr4=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=cA/IzGhK17WDeCv7tdCcRLQFW79uNqyYRIehaLJxTU4mER7nWMrg4J52hwOOnMQ7d y3P12OCaCxGYIQb8FkolzbFh4np2zmANfHmuYVD8n9A6GZYfQPMAAFx/P+tEQGAM3C IuCDJ7zoNuFyIW+4PA1wYOGL8XJTrjM6gZBxLo84GZITi2kGvaBJtPzG+fc9F8S+xq dBea/g/ocDDgqiNjFUIufWXAudP9K2REo3ChgTgOObN8WyyTIUx6SBVD4SBybPEFGx IUCOt/DGYagls2AKjM94UQeWZ3BnXGKpxr+ymX3tB8rg4p5ra5Mh30oUTEOx56hwcL eFgj3XkX9PPdA== Message-ID: Date: Wed, 26 Feb 2025 08:20:02 -0700 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net-next v5 3/9] net: devmem: Implement TX path Content-Language: en-US To: Mina Almasry Cc: Paolo Abeni , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, virtualization@lists.linux.dev, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org, Donald Hunter , Jakub Kicinski , "David S. Miller" , Eric Dumazet , Simon Horman , Jonathan Corbet , Andrew Lunn , Jeroen de Borst , Harshitha Ramamurthy , Kuniyuki Iwashima , Willem de Bruijn , Neal Cardwell , Stefan Hajnoczi , Stefano Garzarella , "Michael S. Tsirkin" , Jason Wang , Xuan Zhuo , =?UTF-8?Q?Eugenio_P=C3=A9rez?= , Shuah Khan , sdf@fomichev.me, asml.silence@gmail.com, dw@davidwei.uk, Jamal Hadi Salim , Victor Nogueira , Pedro Tammela , Samiullah Khawaja , Kaiyuan Zhang References: <20250222191517.743530-1-almasrymina@google.com> <20250222191517.743530-4-almasrymina@google.com> From: David Ahern In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2/25/25 11:54 AM, Mina Almasry wrote: > > Will do, although I think maybe I'll add that comment above the > refcount_t definition in net_devmem_dmabuf_binding, if that's OK with > you. That was meant to explain how the refcounting on the binding > works. > That is fine, I just think the lifecycle of the dmabuf and what the unbinding is really doing should be clearly documented to avoid surprises. > Maybe worthy of note, this is not that new, in fact something similar > is happening in the RX path. In the RX path each skb waiting in the > receive queue to be recvmsg()'d will hold a reference on the > underlying page_pool, which in-turn holds a reference on the > underlying dmabuf. It's just that a similar thing is happening in the > TX path. >